JPS6137830Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a refrigeration cycle equipped with two main and sub hermetic electric compressors, and particularly to an improvement of this type of air conditioner.

Fig. 1 shows a conventional air conditioner of this kind. 1 is a main hermetic electric rotary compressor, 2 is a sub-hermetic electric rotary compressor, and 3 is both electric compressors connected in parallel. A four-way valve for switching the circulation system between heating and heating; 4 is an outdoor coil that acts as a condenser during cooling and an evaporator during heating; 5 is a throttle valve; and 6 acts as an evaporator during cooling and a condenser during heating. This is an indoor coil that acts as a

Both the main and sub hermetic electric compressors 1 and 2 have the same configuration, and are entirely enclosed in housings 1a and 2a, with a lubricating oil reservoir 1 at the bottom for storing lubricating oil.
There are b and 2b. In addition, motors 1c and 2 are provided in the upper part.
compressors 1d and 2d driven by motors 1c and 2c are provided in the intermediate portion. These compressors 1d and 2d have a cylinder 1, for example.
Rotors 1f, 2f eccentrically arranged in e, 2e
It is a rotary compressor with Compressor 1d, 2
d has a suction port 1g that takes in refrigerant gas from the outside;
2g are formed, and discharge boats 1h and 2h are formed for discharging compressed refrigerant gas into the housings 1a and 2a. Further, the housings 1a, 2a are formed with discharge ports 1j, 2j for discharging the internal refrigerant gas to the outside.

Then, the discharge ports 1j, 2j of the electric compressors 1, 2
are connected in parallel to the four-way valve 3 by a branch pipe 7.
Further, the four-way valve 3, the outdoor coil 4, the throttle valve 5, the indoor coil 6, and the four-way valve 3 are connected by conduits 8 to 10, respectively. Further, the four-way valve 3 and the suction ports 1g, 2g of the electric compressors 1, 2 are connected in parallel through a branch pipe 11. Furthermore, the lubricating oil reservoirs 1b and 2b of each electric compressor 1 and 2 are connected to the communication pipe 12.
communicated by.

The conventional device having such a configuration operates as follows. That is, during cooling, the main hermetic electric compressor 1 operates, the sub hermetic electric compressor 2 is stopped, and the four-way valve 3 forms a flow path shown by a solid line. The refrigerant gas inhaled from the suction port 1g is transferred to an eccentric rotor 1f driven by a motor 1c.
is compressed within the cylinder 1e and discharged into the housing 1a from the discharge port 1h. The discharged refrigerant reaches the discharge port 1j while cooling the motor 1c, is guided to the outdoor coil 4 via the branch pipe 7, the four-way valve 3, and the conduit 8, and is condensed by heat exchange with the outside air.

The condensed refrigerant is led to the throttle valve 5 through the pipe line 9, where it is depressurized, and further evaporated by the indoor coil 6, and then returned to the suction port 1g through the four-way valve 3 and the branch pipe 11, and the same cycle is repeated thereafter. Let's do it.

In the case of heating, the four-way valve 3 is switched to form the flow path shown by the broken line, so the main hermetic electric compressor 1
The refrigerant discharged from the is supplied to the indoor coil 6 through the four-way valve 3, condenses, passes through the throttle valve 5, evaporates in the outdoor coil 4, and returns to the suction port 1g via the four-way valve 3 and branch pipe 11. This is what we do.

Now, the auxiliary hermetic electric compressor 2 is operated only when an increase in compression capacity is required, such as during heating when the outside temperature is low, during defrosting, during warm-up operation, and at the beginning of operation. It is not operated and is stopped during cooling or normal heating. However, since the main hermetic electric compressor 1 is connected to the auxiliary hermetic electric compressor 2 through the branch pipe 7, the pressure of the refrigerant gas discharged from the main electric compressor 1 is reduced through the discharge port 2j. It is transmitted to the inside of the auxiliary electric compressor 2. Since the auxiliary electric compressor 2 is stopped, there is no internal heat generation and it is in a cold state. Therefore, the refrigerant inside it is at a high pressure and low temperature, and the refrigerant condenses into the lubricating oil reservoir 2.
It will dissolve into the lubricating oil collected in b.
As the amount of refrigerant dissolved in the lubricating oil increases, the amount of refrigerant in the refrigeration cycle becomes insufficient, causing a reduction in cooling or heating performance. Additionally, if the auxiliary electric compressor 2 is started with a large amount of refrigerant dissolved in the lubricating oil, the lubricating oil will be diluted and the lubricating oil capacity will be insufficient, which could cause the compressor to malfunction. There was a fear that it might trigger.

The present invention was developed based on these circumstances, and its purpose is to provide an air conditioner that prevents refrigerant from dissolving into the lubricating oil of the auxiliary hermetic electric compressor when it is stopped.

An embodiment of the present invention will be described in detail below with reference to FIG.

In the air conditioner of the present invention, whereas in the conventional device the discharge ports 1j, 2j of the main and auxiliary electric compressors 1, 2 are connected in parallel to the four-way valve 3 via the branch pipe 7, the main electric compressor The refrigerant gas discharged from the discharge port 1j of the main and sub-electric compressors 1 and 2 is once introduced into the sub-electric compressor 2, and the discharge port 2j of the sub-compressor 2 is connected to the four-way valve 3. The device is unique in that the discharge port sides of the devices are connected in series, and the rest is almost the same as the conventional device. Therefore, in Figure 2, the first
Components that are the same as those in the figures are designated by the same reference numerals, and explanations of those portions will be omitted.

In the present invention, an opening 20 is formed in the casing 2a of the auxiliary hermetic electric compressor 2 so as to be located below the motor 2c and above the compressor 2d. The outlet 1j is connected to the outlet 1j by a conduit 21. Then, only the discharge port 2j of the auxiliary hermetic electric compressor 2 is connected to the four-way valve 3 through the pipe 22.
is connected to.

In the device of the present invention configured in this way, the discharge port 1j of the main electric compressor 1 is not discharged both during cooling when the auxiliary electric compressor 2 is stopped and only the main electric compressor 1 is operating, and during normal heating. The refrigerant gas is introduced into the auxiliary electric compressor 2 from the opening 20 through the pipe line 21. Therefore, this refrigerant gas cools the motor 2c by passing between the motors 2c (the refrigerant gas discharged has a high temperature, but since the motor has an even higher temperature, it is cooled by this refrigerant gas). It is sent to the four-way valve 3 from the discharge port 2j. From the four-way valve 3 through the outdoor coil 4, throttle valve 5, indoor coil 6, etc., the main and auxiliary electric compressors 1,
The operation when returning to step 2 is the same as before. In this way, the refrigerant gas discharged from the main electric compressor 1 always circulates through the auxiliary electric compressor 2.
The inside of the auxiliary electric compressor 2 is maintained at a high temperature. Therefore, the amount of refrigerant that condenses and dissolves into the lubricating oil is extremely reduced, and problems such as a decrease in the amount of refrigerant in the refrigeration cycle or dilution of the lubricating oil do not occur.

In addition, when it is necessary to increase the compression function such as for heating when the outside temperature is low, the main and auxiliary electric compressors 1 and 2 will be operated together, but in this case, the auxiliary electric compressor 2 The refrigerant gas sucked in from the suction port 2g is compressed by the compressor 2d and discharged from the discharge port 2h into the housing 2a, where it joins with the refrigerant gas introduced from the main electric compressor 1 through the opening 20, and the motor It flows upward while cooling the gas 2c and is discharged from the discharge port 2j, and the same cycle is performed thereafter.

During these operations, the lubricating oil may move as the refrigerant moves, but since the communication pipe 12 is provided, the amount of oil in both electric compressors 1 and 2 is maintained at an appropriate level.

As detailed above, according to the present invention, when only the main electric compressor 1 is operated, refrigerant dissolves into the lubricating oil of the auxiliary electric compressor 2, resulting in a shortage of refrigerant in the refrigeration cycle. can be prevented. Furthermore, since the motor 2c of the auxiliary electric compressor 2 is always cooled with refrigerant gas, the temperature rise of the motor can be reduced and efficiency can be improved.

The present invention is generally applicable to air conditioners, chillers, refrigerators, etc., which have a high-pressure refrigerant side inside the housing (dome) and a hermetic compressor that discharges compressed gas into the dome.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a conventional air conditioner, and FIG. 2 is a system diagram showing an embodiment of the air conditioner according to the present invention. 1... Main hermetic electric compressor, 2... Sub hermetic electric compressor, 1a, 2a... Housing, 1b, 2
b...Lubricating oil reservoir, 1c, 2c...Motor, 1d,
2d... Compressor, 3... Four-way valve, 4... Outdoor coil, 5... Throttle valve, 6... Indoor coil, 11...
Branch pipe, 12... communicating pipe, 21... conduit.

Claims (1)

[Scope of utility model registration request] Each has a lubricating oil reservoir at the bottom, a motor at the top, and a compressor driven by the motor to compress refrigerant gas at the middle. In a refrigeration cycle having first and second hermetic electric compressors, a condenser, a throttle, and an evaporator housed in A conduit for suction in parallel to the electric compressor is provided, and a discharge pipe of the first hermetic electric compressor is communicated with the housing of the second hermetic electric compressor, and the second hermetic electric compressor A refrigeration cycle characterized in that a discharge pipe of an electric compressor is connected to the condenser.